In daily life, a blower is a common tool, usually used to clean up gardens, streets and other grounds.
For example, U.S. Pat. No. 4,880,364 discloses a blower, including a housing, a motor, a fan and an air duct. The fan rotates to generate air flow that exits out of the air duct. However, the fan of such a blower uses a centrifugal fan, an inlet is disposed in a direction along a rotation axis of the centrifugal fan and an outlet is disposed in a radial direction of the centrifugal fan. Owing to the limitation of the structure of the centrifugal fan per se, the volume of air exiting is often not great, and thus the blowing effect is not good, which cannot well meet users' demands.
For example, U.S. Pat. No. 5,975,862 discloses a blower that uses an engine as power, wherein the engine uses gasoline as fuel to serve as power, and the fan is still a centrifugal fan. However, as the power of the engine is greater than that of the general motor, the engine can drive the centrifugal fan to rotate at a higher rotating speed, thus outputting greater air volume and air velocity and meeting users' demands to some extent. However, as the blower using a gasoline engine often has greater work noise and uses gasoline to supply energy, it is easy to form atmospheric pollution, which is not environment-friendly enough.
For example, U.S. Pat. No. 7,739,773 discloses a blower, including a housing, an engine, a fan and an air duct. The fan changes to an axial fan. The engine still takes gasoline as power, and drives the axial fan to work through a transmission unit. However, the engine is disposed outside the housing, to cause the engine to be farther from the fan, and the volume of the whole blower seems to be greater; in addition, the engine is bulky, and does not conform to the portable and lightweight development trend. Moreover, the power source of the engine is still gasoline, which is easy to pollute the atmospheric environment.
Also, for some blowers on the market, the motor is disposed in the housing, used for driving the fan to rotate. The air duct includes an inlet and an outlet, and the air enters from the inlet and exits out of the outlet. In order to make the outlet blow out greater air volume, the fan is preferably an axial fan. The air duct is further internally provided with a duct that guides the air flow formed by the axial fan to move. In order to make the blower keep a compact structure, the motor is disposed in the duct. As the motor per se has a certain size, the duct must be provided with a sufficient size to accommodate the motor. However, the disadvantage brought about is reduction of the work efficiency of the whole blower.
Therefore, it is necessary to improve the existing technical means.